Composed in 1870 this very personal poem mourning the loss of his wife was discovered among Longfellow's effects three years after his death in 1882. It's about his beloved second wife Franny and the reference to martyrdom by fire is a literal one. She perished tragically in their parlor when her dress caught fire while she and her daughter were sealing envelopes using a candle and hot wax. Nearly consumed by the flames, she died later that evening from shock. Longfellow was badly injured trying to save her and eighteen years later he sat in the same room and penned this sonnet.

The Cross of the Snow is at an altitude 14,005 feet,located approximately 100 miles west of Denver and about 15 miles south of Vail, Colorado in the Sawatch mountain range. Longfellow had been browsing through a book of western scenery when he was inspired by a picture of it. In the summertime from a certain angle on the east face of Notch Mountain an image of an almost perfect snow cross emerges and remains visible until autumn.